eickemeyer



t e e h S s t e e h S S 2 R 0 T O M Kw ER T Ym EL ME Bm K CF TLB Ew .m RD Y T E F A s u d .o M 0 N\ No. 538,669. Patented May '7, 1895.

0o N @wf/@Ma n ya@ fm f JUfmHD R. EICKEMEYER. SAFETY DEVICE ECE ELECTRIC MCToEs.

2 Sheets-Sheet 2.

(No Model.)

No. 538,669. Patented May '7, 1895.

UNITED STATES PATENT OFFICE.

RUDOLF EIOKEMEYER, OF YONKERS, ASSIGNOR TO THE OTIS BROTHERS ttf COMPANY, OF NEV YORK, N. Y.

SAFETY DEVICE FOR ELECTRIC MOTORS.

SPECIFICATION forming part f Letters Patent NO. 538,669, dated May '7, 1895.

Application filed July 1S, 1892. Serial No. 439,908. (No model.)

To all whom it may concern: Figure lis a diagrammatic illustration of one Be it known that I, RUDOLF EICKEMEYER, embodiment of my invention suflicent to ena citizen of the United States, and a resident able those skilled in the art to make and use of Yonkers, Vestchester county, New York, the same. Fig. 2 is asimilar View of a slightly- 5 have invented certain new and useful Immodified arrangement. 55 provementsin SafetyDevices for Electric Mo In the drawings plus and minus represent tors, of which the following is a specification. the main leading wires of a system or circuit My invention relates to safety devices for of distribution over which the current passes shunt or compound motors, and it has for its to operate the motor X, which is shown dia- Io object to provide means whereby an electric grammatic ally,andis adapted to be connected 6o motor, in which the eld magnet coils are to an elevatoror hoisting apparatus, or to any wound in shunt, or in which they are wound other working device. in shunt and series as in compound motors, The safety device comprises, as shown in is automatically cut out of circuit in case the the drawings, au iron core A, which is susshunt should be disabled or deranged in any pended from a support B, by a rod C, and car- 65 manner and accidents thereby prevented. ries a detent device D in the shape of a roller.

It is well known that a shunt wound mo- This detent engages with a projection or nose tor will maintain an approximately constant E, on a rod F, which is shown as pivoted at G, speed under all variations of load, and even and carrying at ils free end a weight H, the

zo when it is doing no work, and, in the case weighted rod being supported in its normal 7o where the motor is used for elevators or hoistposition by the nose resting on the detent on ing machineryand the cageis descending, the the rod C. motor maybe driven by the descending load, Arranged with relation to the rod A, as at and the motor will still maintain-a practically one end thereof, is a magnet or solenoid I,

constant speed. It is also well known that in which is connected in the shunt circuit of the 75 a series wound motor, the speed Varies in ac motor X, in the mannerhereinafter set forth, cordance with the load, and will under light and arranged so as to hold the core A in its or no load reach a dangerously high speed. normal position with the rod C against asnit- It is, therefore, with the object of providing able stop or pin K. Arranged with relation 3o safety devices for use with such motors, esto the other end of the arm, is a magnet or 8o pecially in connection with hoisting or elevatsolenoid L, which is connected in the main ing devices, that my invention is made, and or armature circuit of the motor X, in the while it is especially applicable to such uses, manner hereinafter indicated. These two it will be understood that my invention is solenoids I and L are arranged and adjusted not limited in this respect, as it may be used so that with the maximum permissible arma- 85 with any system of compound or pure shunt ture current, the solenoid i, will overpower motors, and can be arranged not only to guard the solenoid L, and hold the core A in its noragainst accidents due to the derangement of mal or vertical position, but if by chance the the shunt, but also against excessive or abshunt circuit is broken or deranged so that it 4o normal currentin the motor, as the dimensions is not acting properly, the core A will be 9o of the relative parts being properly propormoved to the right by the excess of current tioned, the safety devices will operate whenin the solenoid L, even if that excess is but ever the armature current exceeds a safety slight, and the device operates automatically limit. to short circuit the motor and line so that the My invention consists in the means submotor will act asaseries dynamo under short 95 stantially hereinafter more particularly set circuit, which as is well known will operate forth, arranged and operating substantially as a brake, and this is especially advantain the manner described and for the purpose geous in the use of the motor in hoisting or set forth. V elevating devices. At the same time the line 5o Referring to the accompanying drawings, circuit being short circuited, the safety fuse roo 2 eaeee will be burned out and the motor be entirely v disconnected from the line.

While of course this safety device may be used in various connections and circuits, I have shown in Fig. 1, one simple arrangement which has been found to be etfective. Thus from the plus leading wire, the line l leads to a switch or cut-out P, and includes a safety fuse O, and from the switch the wire 3 leads to the solenoid L, and thence by wire 4 to the eld magnet coils Q of the motor X, which are shown as arranged in series, and thence by the wire 5 to the resistances R, and thence through more or less of these resistances according to the position of the brush T, which is controlled by the solenoid U, and constitutes the well known Eickemeyer safety attachment, the operation of which is well understood by those skilled in the art, and thence through the Wire 6, around the coils of the solenoid U, wire 7, to the reversing commutator or switch V, and thence either in one or the other direction4 through the commutator s, and armature S of the motor X, and thence over wire S to the minus conductor of the main line. The branch or shunt circuit passes from the wire 3 over the Wire 9, through the coils of the solenoid I, thence by the wire 10, through the shunt field magnet coils WV of the motor, and by the wire 11, to the wire S, and back to the main line. Also connected to the positive wire 3, is a wire 12, the free end of which is connected to a contact piece M, carried by the arm F, while arranged within the range of movement of this arm is another contact piece N, connected by a wire 13 with a minus main line conductor. Under these conditions when the motor is operating normally, the safety device is in the position shown with the rod resting against the contact K, and the strength of the solenoids I and L are so proportioned that under all conditions of normaloperation, the solenoid I will predominate and hold the core A, in the position shown, but if, for instance a break should occur in the shunt circuits 9, 10 and 11, or other derangement, should distribute the balance of the current flowing through the shunt and the main line, the solenoid L, willbe energized in such a manner as to draw the core A, toward it and this will release the rod F by the detent D passing out from under the nose E, and allow the weight to cause the rod to drop, so that. the contacts M and N will come together, short-circuiting the mainline, and the line current passing from the plus leading wire through the wire 1, the safety fuse O, the switch P, and the wires 12 and 13, through the contacts M and N, will increase enormously by the short circuit, and the safety fuse O will melt, thereby cutting the line off, While the motor circuit will be closed upon itself, and the motor will generate a current as a series dynamo, which will flow from the armature through the coinmutator V, Wires S and 13, through the contacts M and N, wires 12, 3 to the solenoid L,

and thence by the wire t, through the series field magnet coils Q and by the wire 5 through the safety device R, T, and U, and thence back to the armature by the wire 7.

In the arrangement of circuits indicated in Fig. 2, the series field coils Q, are shown as connected to two bars of the controlling or safety switch Y, instead of one of the resistances R, as in the first instance, and at the same time this circuit includes a few turns, as U, of the coils of the controlling solenoid U, so that the series field Q, is in circuitonly when the motor starts, or runs under a heavy load, but is cut out of circuit as soon as the controlling switch operates, and at the same time of course the turns U of the solenoid are also eliminated from the circuit. The resistance device R, is in the present instance composed ot' a number of blocks Z1, Z2, U2, the., insulated from each other, and each pair connected by a resistance conductor r, r', d50., except that in this instance, the block b3 is not connected to its adjacent block by a rcsistance device, but is connected to the conductor 15, leading to the coil U,of the solenoid, and to the series field coils Q of the motor, the other terminal of the series field coils t being connected to the next adjacent block D7. From this it will be seen that when the brush T is in the position shown, the series field magnet coil Q is included in the circuit, but when the brush T moves upward toward the block b, the field magnet coil Q will be cut out of circuit. In this arrangement also the bar B is shown as carrying a contact M, which normally engages the contact N', connected to the wire 3. Under these conditions, the path of the current may be traced from the main leading wire tothe safety fuse and switch O, P as before, by the wire 3, through the contacts N N, the wire 12, through the solenoid L, wire 14, through the resistances R, more or less as the case may be, and by the wire 4, through the series field Q, and back by the wire 5, to and vincluding the solenoid turns U', and thence by the wires 15, G, and 16, through the remaining coils of the solenoid U, to the commutator B, and thence through the armature and out as before; but if, perchance, the brush T should move to the top of the resistance device R, the current would pass directly from the wire 14, through the brush T, the wire 1G, and the coils of the solenoid U, to the reversing switch V, and on as before, thereby shortcircuiting the series field magnet coils, and the shunt field magnet coils NV, will be included in the circuit, the same as set forth in connection with the rst arrangement. If under these conditions, through an excess of current, or other derangement of the parts, the core A, should move away from its stop, the bar F, will fall, breaking the circuit between the wires 3 and 12, and short-circuiting the main line by closing the contacts M and N, and the same results may be produced as in the first instance.

It will be understood that when the main IOO IIO

line is short circuited and the safety device operates, the motor cannot be started again until the rod has been raised by hand, and the parts made to assume their normal positions.

From the above description the general principles of my improved safety device Will be clearly understood, and its application to motors in general, and more especially to motors used in connection with hoisting and elevating devices, Will be appreciated, and while I have set forth the preferred forni, it will be understood that the details of construction and arrangement may be varied by those skilled in the art, Without departing from the general principles of my invention, and I do not therefore limit myself to the precise construction shown.

What I claim isl. The combination With a shunt motor, of a safety device including both branches of the circuit of the motor and arranged to short circuit the motor on disturbance in the balance of said circuits, substantially as described.

2. The combination With a shunt motor, of a safety device having a magnet included in both branches of the circuit of the motor, and mechanism controlled by said magnets for automatically short circuiting the motor on disturbance of the balance of said magnets, substantially as described.

3. The combination with a shunt motor, of a safety device comprising the core, coils controlling said core, and arranged in the circuits of the motor, and a short circuiting device controlled by the movements of the core, substantially as described.

4. The combination with the main line, of a shunt motor connected thereto, a fusible cutout between the main line and motor, a safety device having coils included in both branches of the motor and arranged to automatically short circuit the motor and main line on disturbance of the balance of the circuits of the motor,substantially as described.

5. The combination With the main line, of a shunt motor connected thereto, a safety device interposed between the motor and main line, the safety device comprising a core, and coils included in the branches of the motor, and a short circuiting device controlled by the core, substantially as described.

6. A safety device for motors comprising a core, coils included in the branch circuits of the motor, an arm connected to the mainline, a detent controlling said arm and controlled by the core, and a contact for the arm also connected to the main line, substantially as described.

7. A safety device for electric motors comprising a core, coils connected in the branch circuits of the motor, a pivoted arm supporting the core, a Weighted arm connected to the main line, a detent controlling said Weighted arm, a contact on the weighted arm, and a contact connected to the main line, substantially as described.

8. The combination with the main line, of a compound Wound motor connected thereto, a safety device having tivo coils, one of Which is in circuit With the shunt iield magnet coils of the motor, and the other of which is in eircuit with the eld magnet coils of said motor, the Whole arranged to short circuit the motor on derangement of the circuits, substantially as described.

9. The combination With the mainline and a compound Wound motel` connected therewith, of a safety device interposed between the line and motor, and having acoil in each branch circuit of the motor, and a safety resistance included in the series circuit of the motor,a portion of the coils of the controlling magnet of the safety resistance being included in the series circuit of the motor, and arranged to be short circuited by the safety resistance device, substantially as described.

In testimony whereof I have signed my name to this specification in the presence of two subscribing Witnesses.

BUD OLF EICKEMEYER.

Witnesses:

EMIL GARNJosT, JAMES E. IRVINE. 

